/* Filename: 5sec.c
 * Description:
 * Last modified: humble 20200328 23:55
 */
#include <stdio.h>
#include <stdlib.h>
#include <time.h>
#include <sys/types.h>


static void usage(void);

int main(int argc, char **argv)
{
    int64_t count = 0;

    if(argc != 1){
        fprintf(stderr, "argc !=1");
        usage();
        exit(1);
    }

    time_t end = time(NULL) + 5;

    while(time(NULL) <= end){
        count++;
    }

    printf("%ld\n", count);
    return 0;
}

static void usage(void)
{
#define USAGE "Usage:\n\
  Helloworld\n"
    printf(USAGE);
}
